This invention relates to the field of oil and gas wells, and, more specifically, to oil and gas wells having relatively low gas pressures insufficient to raise a column of liquid out of the well.
Gas and oil wells become unproductive because existing gas pressure in the production zone is reduced by natural depletion to a level which cannot force liquids, in most cases water or oil, from the well, thereby creating a liquid plug and blocking further recovery of gas and liquid products. It would therefore be desirable to be able to raise the liquid from the well utilizing the gas pressure existing in the well. Further, it would be desirable to provide a device able to accomplish this task without moving parts and without the introduction of additional energy, in any form, into the well.
The invention comprises a multi-level liquid elevator having a plurality of vertically-stacked stages. Each of the stages is of a length which is compatible with the available pressure in the well. That is, the pressure in the well is sufficient to push liquid at least the length of the stage. This allows the liquid blocking the well and the liquid and gas products available in the well to be raised, stage by stage, to any desired elevation, thereby freeing the well for renewed operation.
The invention as described may also be utilized for other applications requiring the raising of liquid, such as the filling of a standpipe on a tall building utilizing a small air compressor instead of a large motor driven pump or a series of pumps.